You probably know these things already. People keep reporting it, with the implication that student debt is out of control, that there is some kind of crisis building.

But it turns out that the rise in total student debt is not primarily the result of each student borrowing more money. It's the result of more students going to college.

"The main force pushing up the total amount of outstanding student debt is growth in the number of people going to college," said Sandy Baum, an analyst at the College Board.

Average debt per college graduate is rising — but not nearly as fast as total student debt.

These graphs show average debt per student for bachelor's degree recipients, by year. You can find this data and much more in College Board's 2011 report on trends in student aid (see page 19 for the source for these graphs).

These are, of course, only averages. There are some students who get through college without any debt at all. Others owe much, much more than the average. This post from the Atlantic has a nice discussion of the distribution.

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